A prototype transmit/receive module on a single 6x6 mm chip, intended to deliver miniaturised space radar systems for future missions.
Traditional transmit/receive modules used on Europe’s Sentinel-1 and comparable radar missions employ separate circuits for the high-power amplifier, the low-noise amplifier and the switch/isolator.
The aim, developed for ESA by TNO in the Netherlands, UMS in France, and Airbus Defense and Space in Germany, was to integrate all these functions onto a single chip, while delivering increased efficiency and a threefold increase in radio-frequency power.
The added ingredient enabling this was that the chip was made using gallium nitride (GaN) – the most promising semiconductor since silicon. If you have a Blu-ray player than you own a tiny crystal of GaN, used in high-performance blue lasers.
GaN can operate with high radio-frequency output power, low noise or at much higher temperatures than silicon. As a plus, it is also inherently resistant to radiation. ESA has been leading the industrialisation of GaN through the GaN Reliability Enhancement and Technology Transfer Initiative consortium.
A follow-up project to integrate the chip into a complete radar module suitable for a future Sentinel-1 successor mission is being undertaken through the Agency’s follow-up General Support Technology Programme.